NEBDN Dental Nurse practice questions and answers 2026. Tap an option to test yourself — you'll see the correct answer and a plain-English explanation for every question. Free, no login.
Q11A dentist states that tooth 14 requires treatment. What should the dental nurse do to prepare?
✓ Correct answer: A. Set up for treatment of the upper right first premolar
FDI tooth 14 belongs to quadrant 1 (upper right) and is at position 4, which is the first premolar. Why the other options are incorrect: • Set up for treatment of the upper left first premolar: The upper left first premolar is numbered 24, not 14. • Set up for treatment of the lower right first premolar: The lower right first premolar is numbered 44. • Set up for treatment of the upper right second premolar: The upper right second premolar is numbered 15. • Set up for treatment of the lower left first premolar: The lower left first premolar is numbered 34.
Q12A patient requires root canal therapy because of a tooth infection. Which tooth structure is removed during this treatment?
✓ Correct answer: C. Pulp
During root canal therapy, the infected pulp tissue is removed from within the tooth. Why the other options are incorrect: • Enamel: Enamel is preserved and not targeted during root canal treatment. • Dentine: Dentine is kept intact as much as possible throughout the procedure. • Cementum: Cementum on the root surface is not removed during this treatment. • Gingiva: The gingival tissue is not involved in root canal therapy.
Q13Based on the image, which structure encircles the root and connects it to the surrounding bone?
✓ Correct answer: C. Periodontal ligament
The periodontal ligament runs between the root surface and the alveolar bone, securing the tooth within its socket. Why the other options are incorrect: • Gingiva: The gingiva encircles the tooth at the gum line but does not link the root to bone. • Enamel: Enamel is restricted to the surface of the crown. • Dentine: Dentine is an internal tooth layer and does not form any bony attachment. • Pulp: The pulp is the central soft tissue of the tooth.
Q14A dental nurse reviews a radiograph showing breakdown of tooth-supporting structures. Which tissue is chiefly responsible for anchoring the tooth within its socket?
✓ Correct answer: C. Periodontal ligament
The periodontal ligament connects the root to the alveolar bone, providing anchorage and distributing biting forces. Why the other options are incorrect: • Enamel: Enamel is a protective outer coating and plays no role in tooth attachment. • Pulp chamber: The pulp chamber is the neurovascular core of the tooth. • Dentine: Dentine contributes to the tooth's bulk but does not secure it within the socket. • Gingiva: The gingiva covers and protects surrounding tissue but does not anchor the tooth to bone.
Q15Which sequence correctly lists the layers of the tooth crown from the outermost surface to the centre?
✓ Correct answer: B. Enamel → Dentine → Pulp
The correct order moving from surface to centre is enamel on the outside, dentine in the middle, and pulp at the core. Why the other options are incorrect: • Dentine → Enamel → Pulp: Dentine is the middle layer, not the outermost. • Pulp → Dentine → Enamel: Pulp is the innermost structure, not the outermost. • Enamel → Pulp → Dentine: Pulp lies at the centre and is not positioned between enamel and dentine. • Cementum → Enamel → Pulp: Cementum covers the root and does not form part of the crown layer sequence.
Q16Following enamel erosion, a patient reports severe cold sensitivity. Which underlying structure is most likely responsible for conducting this sensation?
✓ Correct answer: B. Dentine
Dentine houses microscopic tubules that carry stimuli to the pulp; when these tubules are unprotected, the patient experiences sensitivity. Why the other options are incorrect: • Enamel: Enamel is an inert, acellular tissue incapable of transmitting sensation. • Cementum: Cementum is a root-surface covering and plays no significant part in sensory transmission. • Alveolar bone: Alveolar bone forms the tooth socket but does not conduct sensory signals from the tooth. • Gingiva: The gingiva shields surrounding structures but does not transmit tooth sensation.
Q17A dental nurse records a lower right canine as tooth 43 in the FDI system. What is the accurate FDI designation for this tooth?
✓ Correct answer: E. 43
Tooth 43 is indeed the correct FDI number for the lower right canine, so the recording contains no error. Why the other options are incorrect: • 33: 33 denotes the lower left canine, not the lower right. • 13: 13 denotes the upper right canine. • 23: 23 denotes the upper left canine. • 44: 44 refers to the first premolar in the lower right quadrant.
Q18On a maxillary incisor, which surface is directed toward the roof of the mouth?
✓ Correct answer: B. Lingual surface
The lingual surface of upper incisors faces the palate, which forms the roof of the mouth. Why the other options are incorrect: • Labial surface: The labial surface faces the lips, not the palate. • Buccal surface: Buccal surface is a term applied to posterior teeth facing the cheeks. • Occlusal surface: Incisors do not have an occlusal surface; they have an incisal edge instead. • Mesial surface: The mesial surface faces toward the midline of the arch, not the palate.
Q19Based on the tooth image provided, which surface is most susceptible to plaque accumulation due to its pits and fissures?
✓ Correct answer: C. Occlusal surface
The occlusal surface contains pits and fissures that create ideal conditions for plaque to accumulate. Why the other options are incorrect: • Buccal surface: The buccal surface is relatively smooth and less prone to fissure-related plaque retention. • Lingual surface: The lingual surface generally lacks the deep pits and fissures characteristic of the occlusal surface. • Mesial surface: The mesial surface is a contact area between adjacent teeth, not a fissured chewing surface. • Distal surface: The distal surface is also a contact area and does not contain pits and fissures.
Q20Radiographs of a patient with periodontal disease reveal significant bone loss around multiple teeth. Which structure is primarily being destroyed?
✓ Correct answer: B. Alveolar bone
Alveolar bone forms the bony socket housing the tooth roots and is the principal structure lost in progressive periodontal disease. Why the other options are incorrect: • Gingiva: The gingiva is soft tissue that, while affected, is not the primary structural support being lost. • Enamel: Enamel is a crown surface layer and has no connection to bone support. • Dentine: Dentine makes up the body of the tooth and is unrelated to bone support. • Pulp: The pulp is the internal neurovascular tissue and plays no role in bone support.
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Theory